Electrical remote control system



H. A. EWEN ELECTRICAL REMOTE CONTROL SYSTEM F iled March 22,

INVENTOR A EN HARY

ATTORNEY Patented Apr. 28, 1936 UNITED STATES PATENT OFFICE HarryAlexander Ewen, Shenfield, England, assignor to Radio Corporation ofAmerica, a corporation of Delaware Application March 22, 1933, SerialNo. 662,121 In Great Britain March 22, 1932 2 Claims.

This invention relates to electrical remote control systems and has forits object to provide a remote control system suitable for the controlof an electric motor or other driving member which is required to bemoved between limits of movement in either of two directions.

Although not limited to its application thereto the present invention isespecially suitable for use for the remote control of electric motorsoperating collapsible aerial structures suitable for use on submarines.Such aerial structures may be operated either manually or by means ofelectric motors and the present invention provides a convenient controlsystem for the control of such electric motors in the latter case.

According to this invention an electrical remote control systemcomprises a reversing switch device controlling the member to becontrolled, means for operating said reversing switch device to changeit over from one position into another and back again, switch contactsadapted to be actuated by the member to be controlled and connected inassociation with the means for actuating the reversing switch device,said switch contacts being so arranged that one is closed and the otheropened when the member to be controlled reaches one extreme of traveland vice versa when the said member reaches the other extreme, manuallyoperable contacts in series with the reversing switch contacts and withthe member to be controlled and a hold-on winding in series with thesaid manually operable contacts for holding said contacts closed (oncethey are closed manually) until the circuit of said hold-on winding isbroken elsewhere.

Preferably an electromagnetic brake is provided for arresting themovement of the member to be controlled and means interlocked with themanually operable contacts are provided for energizing said brake whensaid contacts are open.

The invention will now be described with reference to the accompanyingdiagrammatic drawing as applied to the control of an electric motor forhoisting and lowering an aerial structure.

Referring to the drawing the reversible motor for hoisting and loweringthe aerial structure has its armature which is represented by thewinding B connected across the middle pair of contacts of a reversingswitch device generally designated C which contacts C I, C2, arepermanently connected to the two arms C3, C4 of the switch, theremaining pairs of contacts 05, C6, C1, C8 being cross connected as inthe usual way. A circuit extends from one terminal, say, the positiveterminal of a source of supply, through a hold-on winding W through thenormally open contacts DI, D2 of a manually operable switch D to contactCl, while contact C8 is connected to the negative terminal of supply.The reversing switch device which may in practice take any of a varietyof difierent forms, e. g. it may be constituted by a pair ofelectromagnetic switches, is electromagnetically actuated by means of apair of coils F and R whereby the switch device may be moved into itsforward or reverse position according as to which coil is energized. Acircuit extends from the positive terminal of the source of supply tothe junction point of the two operating coils F R for the reversingswitch device, the other end of the coil F being connected to a fixedcontact X and the other end of the coil R being connected to anotherfixed contact Y. A slidable contact member E is movably mounted betweenthe two fixed contacts X Y so that when said contact member is in oneposition it completes a circuit through one of the reversing switchcoils while when it is in the other it completes a circuit through theother, said circuits being both completed through the slidablei contactmember E to the negative terminal of the source of supply. The slidablecontact member is adapted to be moved back and forth by means of anabutment member G suitably mechanically geared or otherwise driven withthe aerial structure or the motor driving the same so that when saidaerial is moved into one extreme position the contact member E is movedinto a position at which it completes a circuit for one actuating coilof the reversing switch device while when the aerial structure is movedinto its other position, the contact member completes the circuit forthe other reversing switch device coil. An electromagnetic brake Aassociated with the driving motor or with some other part of the drivingstructure is also provided, and this brake is adapted to be energizedfrom the source of supply through pairs of contacts D3, D4, D5, D5 whichare closed when the manually operable contacts DI, D2 are open andopened when said manually operable contacts are closed. The hold-onwinding W is arranged when energized to attract an armature so as tomaintain the manually operable contacts closed when once they have beenclosed. If desired a main or master switch (not shown) may be providedin series in the main lines of supply and resistances AR BR may beshunted across the electromagnetic brake winding and the motor armature.

The operation of the whole device is as follows:

Suppose the reversing switch device is in such a position that when themanually operable contacts DI, D2 be closed the driving motor will bedriven in a direction to hoist the aerial, the slidable contact member Ebeing, of course, in such a position as to complete the circuit of theappropriate reversing switch coil for holding the reversing switchdevice in the appropriate positlon for this direction of movement to beobtained. If now the manually operable contacts DI, D2 be closed by handthe driving motor will start to move in the stated direction, themanually operable contacts being held closed by the hold-on winding W.When the aerial has been hoisted the slidable contact member E will bemoved to open circuit that reversing switch coil which has beenenergized during the movement last described, and will close the circuitfor the other reversing switch coil, the reversing switch device beingin consequence thrown over into its other position. The reversing switchdevice is so arranged that there is a short interval of time between theopening of the motor circuit for driving in one direction and theclosing of the motor circuit for driving in the other, and inconsequence, during this short interval of time, the circuit for thehold-on winding W is broken and the manually operable contacts Dl, D2,permitted to open. Simultaneously with the opening of the manuallyoperable contacts the contacts D3, D4, D5, D6, in series with the brakewinding A are closed and the aerial is accordingly stopped, the motorcircuit being held open at the manually operable contacts DI, D2, andthe reversing switch being held in that position proper for driving themotor to lower the aerial. If now the manually operable contacts beagain closed by hand, the motor will be energized to lower the aerialstructure to be moved from whatever position it happens to be to theopposite position, the motor continuing to run until the said oppositeposition has been reached.

Preferably appropriately coloured indicating lamps Ll, L2, e. g., a redlamp and a green lamp, are associated with the reversing switch coils,the two lamps being connected together on one side, the other terminalof one lamp being connected to the end of one coil, and the remainingterminal of the other lamp to the end of the other coil, the commonterminal of the lamps (like the common terminal of the coils) beingconnected to the positive terminal of the supply. Although the inventionhas been described with reference to the control of the hoisting andlowering mechanism of a submarine aerial structure, it is, of course,not limited to this application. Another application is to the remotere-tuning of a short wave aerial, which may be required to be re-tuned,for example owing to alteration of its impedance due to ice formationthereon. It is, of course, necessary that in a short wave beam orsimilar aerial system that the impedance of the aerial should match thatof the feeder associated therewith and a relatively high degree ofaccuracy of matching is required if alteration in the load on thetransmitter valves of a transmitter associated with such a short waveaerial is to be avoided. The present invention provides a convenientmeans for providing such remotely controlled re-tuning.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:-

1. An electrical remote control system comprising a device to becontrolled, a reversing switch for controlling the device to becontrolled, means for operating said reversing switch from one positionto another and back again, a plu rality of fixed contacts adapted to beactuated by the device to be controlled, said fixed contacts beingconnected and arranged with said operating means so that one contact isclosed when the other contact is open after said device to be controlledreaches a predetermined extreme position of travel, and vice versa whensaid device reaches an oppositely disposed position, a

pair of manually operated contacts connected in i series with saidreversing switch and the device to be controlled, an electromagneticbrake for arresting the movement of said device to be controlled andinterlocking means connected with said manually operable contacts forenergizing said brake when said manually operable contacts are open.

2. An electrical remote control system comprising a device to becontrolled, a reversing switch for controlling the device to becontrolled, means for operating said reversing switch from one positionto another and back again, a plurality of fixed contacts adapted to beactuated by the device to be controlled, said fixed contacts beingconnected and arranged with said operating means so that one contact isclosed when the other contact is open after said device to be controlledreaches a predetermined extreme position of travel, manually operablecontacts connected in series with said reversing switch and the deviceto be controlled, an electromagnetic brake for arresting the movement ofsaid device to be controlled and interlocking means connected with saidmanually operable contacts for energizing said brake when said manuallyoperable contacts are open.

HARRY ALEXANDER EWEN.

